Microsoft has given programmers a peek at the next version of Windows.

Codenamed "Longhorn", the software was shown to developers by Bill Gates, the technology giant's chairman and chief software architect.

Microsoft said the new version will have better security, make it easier to organise and find files and need to be restarted much less often.

Although programmers are getting an early look at Longhorn, it is unlikely to go on sale before 2006.

Programming peep

Longhorn was shown off on Monday at Microsoft's Professional Developers Conference in Los Angeles.

The audience for the demonstration was made up of 7,000 programmers many of whom will be writing applications that take advantage of the new technologies in Longhorn.

Some of the gloss was taken off the unveiling because early versions of Longhorn were leaked on to the net the day before the conference began.

Bill Gates said the release of Longhorn would be Microsoft's largest software launch this decade and would mean big changes to the way Windows works.

He said the creation of Longhorn had been conducted around four key areas:

Security and scalability

Graphics

File storage

Web services

The security changes aim to make Windows less vulnerable to malicious viruses and worms and will give system administrators features for limiting what machines can do and what users can do with particular files or documents.

Windows XP was launched in late 2001

Also included are technologies that speed up the installation of software and make programs launch quicker.

Longhorn will also have a completely re-written presentation system, called Avalon, that removes many of the memory and graphics limitations that remain from earlier, less powerful generations of machines.

Bill Gates said that Longhorn will have a unified storage system called WinFS. This will use web-derived technology to make it possible to search for and categorise any type of file with just one system instead of separate ones for every application.

Such a flexible system would be needed, said Mr Gates, because in the future people are likely to generate 'oceans' of information that they will need to search through quickly.

Finally, Longhorn will have built in many of the technologies needed to make it easy to set up sophisticated web services.

As well as outlining the new technologies in Longhorn, Microsoft also demonstrated how it would look.

One of the key features of the new desktop is a smart panel that sits at the side of the screen and can be configured to hold essential information such as instant messenger buddy lists, time, links to favourite websites as well as news and stock tickers.